Although ncRNAs are defined as RNAs that are not translated into proteins, recent studies have reported that some ncRNAs indeed coded small proteins and those proteins regulated various biological processes.
LOC105354516 is annotated as a ncRNA that is highly expressed in the adult brain of medaka (Oryzias latipes).Reanalysis of publicly available ribosome profiling data revealed that two small proteins are translated from LOC105354516. These proteins were highly homologous to zebrafish Zwilling. Zwilling has been reported to be a myelin protein, but its physiological function is unknown. Therefore, we named LOC105354516 as ozwi and continued to analyze its function.
The expression pattern of ozwi mRNA showed high homology with that of mbpa (myelin basic protein), suggesting that ozwi gene also encoded a myelin protein.
We generated ozwi mutants in which a large portion of the ozwi gene was deleted and performed an open field test using them to evaluate their anxiety-like behavior. Compared to the wild type, ozwi mutants spent more time at the edge of the tank and showed higher anxiety. Furthermore, to explore other physiological function of the ozwi gene, we are currently comparing myelin in WT and ozwi mutants by electron microscopy and searching for proteins that form a complex with the ozwi protein.